Air cells, particularly for pneumatically adjustable occupant support systems in seating or other support applications, are frequently constructed from facing layers of a flexible, air-impermeable material such as thermoplastic urethane, fabric reinforced polyvinylchloride, and other plastic film materials, that are dielectrically sealed or otherwise joined about their marginal edges to enclose an interior inflatable air chamber. An air tube connected to the air cells that in turn is coupled to an airflow control system for inflation and deflation of the air cell.
Traditionally, such air cells are inflated by either pressurizing or deflating one or more of the cells in accordance with a predetermined control algorithm for providing a desired user comfort level. Alternatively, the pressure can be controlled by a pump and switch. In such arrangements the individual air cells have been located in desired seating configurations including the lumbar region and ischial regions of a user. In such seats a further practice has been to perforate an overlying trim material so that the seat cushion or seat back support surfaces will tend to breath. Leather or a suitable plastic material such as PVC, urethane, polyolefins or the like materials have been provided to give a level of so called breathability.
While suitable for their intended purpose such arrangements neither cool or heat a seat to meet desired uniform thermal comfort considerations. Other seating arrangements are known that will heat or cool a seat.
Examples of such arrangements are set-forth in the following listed patents.
U.S. Pat. No. Inventor 5,016,302 Yu 5,524,439 Gallup et al. 5,597,200 Gregory et al. 5,626,021 Karunasiri et al. 5,715,695 Lord 5,800,480 Augustine et al.
None of the aforesaid arrangements, however, provide for heating or cooling the fluid and also controlling the pressurization in known pneumatic support systems that utilize one or more air cells as a means for supporting an occupant and operable to vary the pressure in one or more or the air cells to provide individual occupant comfort.